Usability tests
You have the option to conduct usability tests to assess if users are able to effectively use your product. These are generally done via screen sharing from a desktop or a mobile device.
Before the interview, it's a good idea to prepare a number of smaller tasks for the users, and ask them about their experience with your product.
For usability tests, 5 users seem to be the magic number. These users are usually enough to point out the majority of your key usability issues.
User interviews
User interviews are also a great way to discover if people are interested in your product, website or idea. For this, we have to understand how they usually tackle a specific task or use existing solutions. This should give a deeper understanding of your target audience’s needs and behaviors.
User research generally needs a bit more data to be concise. 5 users should give you a pretty good sense about the viability of your product or idea, but be prepared to conduct further research with additional people to gather more details.
For more detail, check out our article: How Many People Should I Interview?
The main goal is to understand behavior and motivation. The interview or user test is a way to help you better understand what issues your users may be facing. Instead of talking about general ways of doing a given task, try to ask about more specific details. This will help you understand rather than just gathering answers to specific questions.
To take your user interviews to the next level, check out our 7 steps to conducting user interviews that glean actionable insights every time guide.